Sn. Brown et al., Relationship between food deprivation before transport and aggression in pigs held in lairage before slaughter, VET REC, 145(22), 1999, pp. 630-634
Pigs from three farms were deprived of food for up to one hour, 12 hours or
18 hours before being sent for slaughter. In lairage, the animals' behavio
ur was monitored, and at slaughter a blood sample was collected and analyse
d for cortisol, lactate and creatine phosphokinase, potential indicators of
stress and physical activity. The carcases were assessed for skin damage a
s an index of fighting, and rigor in the hind leg as an indicator of stress
and/or fatigue. Measurements were also made of cold carcase weight, backfa
t thickness and liver glycogen concentration. General activity was very hig
h on entry to the lairage pen. Drinking and mounting occurred almost immedi
ately. Fighting developed after an exploratory period, and could last up to
60 minutes. There were large differences in the behaviour of pigs from the
three farms. Pigs from farm A fought frequently but showed little mounting
activity, whereas pigs from farm C were involved in mounting but little fi
ghting. The period of food deprivation had no effect on average skin damage
or rigor score, but the frequency of carcases with the highest scores was
different. The pigs deprived of food for up to an hour had the lowest incid
ence of severe skin damage and high rigor scores. Boars had a higher incide
nce of severe skin damage but a lower incidence of carcases with a high rig
or score than gilts. Liver glycogen was almost completely depleted in the p
igs deprived of food for 12 and 18 hours and was lower in the pigs deprived
for up to an hour than in animals fed immediately before slaughter. The pe
riod of food deprivation had no effect on the levels of cortisol, creatine
phosphokinase or lactate in the blood.